﻿#define  _CRT_SECURE_NO_WARNINGS 1
//喝汽水
#include<stdio.h>
int main()
{
	int money,total,empty;
	scanf("%d", &money);
	total = money;
	empty = money;
	while (empty > 1)
	{
		total = total + empty / 2;
		empty = empty / 2 + empty % 2;
	}
	printf("一共可以喝%d瓶", total);
	return 0;
}